Summary of long rambling post : How do I make a hard disk spin down when idle under Linux, specifically Raspbian/Debian ?
Detail :
So, I thought I'd use my spare Raspberry Pi as a NAS unit, and shove one or more spare hard disks in to serve to the network, using Samba and maybe NFS or other (mostly to be used from Windows PCs, so Samba..)
So far so good, and in quite a short space of time considering my still newbieness with the Pi, I've got it running, serving out one of the SATA disks I've plugged into the USB port via a cheap ebay adaptor cable. Disk powered from an old PC PSU, pi from it's own 5v supply at the moment.
Quick speed test, I can copy files to it at very close to 12Mb/second, which is very pleasing as my actual NAS disk enclosure unit struggles to achieve 4Mb/second. Streaming HD video from the old NAS to another Raspberry Pi running RaspBMC is usually a dismal stuttery affair.
So, goal 1 achieved - faster throughput.
Goal 2 was to be lower power consumption. The slow NAS unit has no facility for this, the disk spins 24/7, it's using about 30 watss all the time.
So, bung it on a Raspberry Pi (running Raspbian/Debian) that'll be simple, won't it? Set the disk idle timer to say 30 minutes, it'll spin down and save electric.
Well, after 2 days of trying I've almost given up. There seem to be many "solutions", and none of them seem to work for me. Nor for many other people. If you google for "hd spin down raspberry pi" (or similar), you'll get lots of suggestions, and many more responses saying "yes, but it doesn't work".
Come on, Microsoft have been doing this since at least Windows 95, if not earlier.
Does anyone here know of a good/reliable/easy-for-idiots-like-me-to-understand way of getting attached hard disks to spin down when idle?
Ian